Requirements:
LED (8 of them)
Possibly Resistor(s)
Wire (30 guage)
GameBit Screwbit
Hot Glue Gun
Phillips Screwdriver
Wire Cutters
Soldering Iron & Solder
Small Metal Tool
Eletrical Tape
To start things off you're going to need to purchase 8 LED and possibly a resistor depending on the LED themselves. Understand that you're going to be using a 12v current as your power supply so if you purchased eight 1.5v LED that would let you get away with not purchasing a resistor as ( 8 LED x 1.5v = 12v ). Now say you purchased 8 LED which are 2.1v each you will need to purchase two 150 Ohm resistors one for each pair of 4 LED.
You'll most likely need to calculate what resistor to get so you can do so using MetkuMod's Current Limiting Resistor Calculator. Now a resistor is going to take the original current (12v in our case) and reduce it down to a lesser current. Using the picture above you can clearly see the LED specifications which are 2.1v (voltage/drop across LED) and 25ma (desired LED current). So you use these variables along with the 12v powersource and the number of LED's to calculate the resitor required which again in this case is a 150 Ohm.
When purchasing the resistor you need please make sure to not buy one that has a 'K' on the end of it as this stands for thousands and will not work.
Below is the correct resitor we need for the job.
If you're ever in need to know how to deterime how to identify a resistor by sight here is a chart.
Next take apart your Cube and then take off the controller assembly. If you need instructions on how to take apart your Cube check here. Next take a close look at one of the ports the controller plugs into and you'll notice four small metal legs one each side. Using your small metal tool push the top and bottom legs out and then cut them off with the wire cutters.
Now using the gun glue one LED on the top and bottom of the of each controller assembly. Since we're going to be using the 'series' method for powering the LED you will need to make sure each LED is facing the same way. I find it makes it easy to identy the negative side of the LED by coloring the leg with a black marker.
As you can see in the diagram below you must face each LED to same way so each '+' leads to a '-'. Next solder all of the connecting LED legs together leaving the ones on the ends alone.
Next locate the '+' and '-' points underneath the power supply and solder wires to them. The power supply is the small board that the power cable from the wall plugs into located on the fan assembly which requires you to remove one phillips head screw to access the bottom. Using the picture below the RED (left) wire is the 12v and the BLUE (right) wire is the '-' or ground.
Now connect both resistors to the wire and then connect each resistor to the '+' (downgraded 12v power) of the first LED. You can solder on the resistors to the wire facing either way as it doesn't matter what way the resistor faces. Next solder on the '-' (ground) wire to the '-' of the end of both strands of LED.
Once you are done test the LED to make sure they are working by just plugging in the Cube and turning it on. Don't worry you don't need to plug in the controller assembly to test the LED. Once everything is working fine route the wire around the Cube (using the same way that you route the Viper GC wires) and re-assemble it!
If you're not wanting to go through the pain of installing this mod yourself you might want to check out AheadGames (USA) which offers various custom cosmetic installations including LED mods.